Locking-lamp.



H. HUBBELL.

LOCKING LAMP.

APPLICATION FILED FEB-1. 1913.

Patented May 4, 1915.

WITNESSES A, (111' (blip/flu,

' ATTORNEY a s'mrns PATENT ornioe.

HARVEY HUIBBELL, F BBIDGEPORT, CONNECTICUT.

LOCKING-LAMP.

Specification of Letters Patent.

Patented May 4, .1915.

Application filed February 1, 1913. Serial No. 745,640.

To all whom it may concern:

- Be it known that I, HARVEY HUBBELL, a

citizen of the United States, residing at Bridgeport, county of Fairfield, State of .Connecticut, have invented an Improvement in Locking-Lamps, of which the following is a specification.

This invention relates to electric lamps and has for its general object to provide-a lamp which may be readily attached to a lamp socket but which, when in place, cannot be detached therefrom, thereby preventing the improper removal or changing of lamps by unauthorized persons.

To this end the invention in the form herein shown and described, comprises a lamp base having means for attachment to a lamp socket in the usual manner, said means however being inoperative to permit detachment of said lamp from said socket.

More specifically, and in accordance with one feature of the invention, said invention contemplates the provision of a 'lam base which may be screwed into an or inary lamp socket but which cannot be unscrewed therefrom without first performing an operation which will destroy the usefulness ofv the lamp.

With these and other objects in view I have devised the novel lamp which I will now describe, reference being had to the accompanying drawing'forming apart of this specification and in which:

Figure 1 is an elevation of a lamp base constructed in accordance with the invention; Fig. 2 is an elevation of the safne part inner-shell on the line 66, Fig. 4; Fig. 7

as viewed from the right in Fig. 1; Fig. 3

is an elevation ofthe same part as viewed from the right in Fig. 2; Fig. 4 is an elevation and Fig. 5. a plan of the inner shell of the lamp base; Fig. 6 is a section of the is a section of the lamp base showing the bulb in elevation, the parts being in attachlng position; Fig. 8 is a similar view showing the parts in detaching position; Fig. 9

1s a plan view of the inner lamp base shell showlng the outer shell in section on the line 9- 9, Fig. 7,-and showing the parts in attaching position; Fig. 10 is a. view similar inner lamp base shell 19 which is normally in contact with an outer lamp base shell 20. The outer shell 20 is corrugated in the usual manner to provide threads 21 bv which the lamp may be screwed into and attached to the ordinary lamp socket. The shells 19 and 20 are both preferably formed of sheet metal; The outer shell 20 is loose or free to turn upon the button 17 and inner shell 19 and is provided with a stop shoulder 22 adapted to cooperate with a stop shoulder 23 on the'inner shell 19.

36 denotes a shoulder on the button 17 which engages an inturned flange 37 on the outer shell 20. The inner shell 19 is preferably recessed, as at 24, to receive the lower end of the button 17 and is provided with a central-opening 25 into 'which project teeth 26 which engage a shouldered insulating. washer 27 carried by the end of the tube or hollow rivet 16, whereby said inner shell is normally rigidly secured to the button 17.

I 28 denotes a double-ended pawl or dog pivoted at 29 to the inner shell 19 and havmg oppositely disposed ends or points 30 and 31 adapted respectively to enter openings 32 and 33 in the. outer shell 20. These openings are ,preferably produced by indenting the threads 21 to form oppositely disposed inturned shoulders 34 and 35, as

shown most clearly in Figs. 1 to 3, and are in different planes or positions longitudi nally of the lamp base, as shown in Fig. 2.

The operation of the device is as follows. The normal position of the parts is as shown in Fig. 7. If the bulb 12 be turned in the,

direction to screw the lamp into a lamp socket engagement'of the end 31 of the pawl 28 with an inwardly projecting portion of the thread 21 causes the end 30 of said dog to be moved outwardly and engage the opening 32 and shoulder 34, thereby causing the outer shell 20 to turn in unison with the inner shell 19, which is rigidly and permanently secured to the bulb 12, and permitting the lamp to be screwed into the socket in the usual way. Turning of the bulb 12 in the opposite direction in order to unscrew the lampfrom the socket will not cause corresponding turning of the outer shell 20, since the point 30 of the dog 28 will move idly over the shoulder 34 and will not enter the recess 32. The inner shell 19 will therefore turn idly within the outer shell 20, so that after the lamp has once been screwed into place it cannot be unscrewed merely by turning the bulb 12. In order to remove the lamp from the socket it is necessary to pull the bulb 12 outwardly with suflicient force to disengage the teeth 26 from the washer 27 and bring the stop shoulder 23 on the inner shell 19 into engagement with the shoulder 22 of the outer shell 20, as shown in Fig. 8, outward movement of the button 17 being prevented by engagement of the shoulder 36 with the flange 37 on the outer shell. This relative longitudinal movement of the lamp base lshell brings the dog or pawl 28 into a position to cooperate with the o ening 33 and shoulder 35. If now the amp bulb be turned in a direction .to unscrew the lamp from the socket, engagement of the end 30 of the do 28 with an inwardly projecting portion 0% the thread 21 causes the end 31 of said dog to enter the opening 33 and engage the shoulder 35, causing the outer shell .40 20 to rotate in unison with the inner shell 19 and permitting the lamp to be removed from the socket. The relative longitudinal movement of the inner andouter shells necessary to bring the dog 28 into a position to engage the opening 33 and shoulder 35, by separating the inner shell from the button 17, causes the conductor 14 to be broken, as shown in Fig. 8, thereby destroying the usefulness of the lamp and defeating the usual purpose of an unauthorized'person in improperly removing a lamp.

Having thus described claim 1. An electric lamp comprising a bulb, an inner lamp base shell secured to said bulb, a contact member connected with but insulated from said inner shell, conductors communicating with said bulb and connected with said contact member and innershell, respectively, an outer threaded lamp base shell mounted to turn on said inner shell, one of said shells having a shoulder, and a pawl pivoted to the other of said shells for engaging said shoulder and causing said outer shell to turn with said inner shell my invention I when said inner shell is turned in one direc- I lated from said inner shell, conductors communicating with said bulb and connected with said contact member and inner shell, respectively, an outer threaded lamp base shell mounted to turn on said inner shell and having a shoulder, and a pawl pivoted to said inner shell for engaging said shoulder and turning said outer shell when said inner shell is turned in one direction.

3. An electric lamp comprisinga bulb, an inner lamp base shell secured to said bulb,

an outer threaded lamp base shell having a pair of oppositely disposed shoulders arranged in different positions longitudinally of said shell, and a pawl pivoted to said inner shell and having oppositely disposed ends adapted to coiiperate with said shoulders respectively, said shells being relatively longitudinally movable'to bring said pawl into a position to engage either of said shoulders.

4. An electric lamp comprising a bulb, a button, a tube passing through said button, a flanged washer carried by the inner end of said tube, an innerlamp .base shell secured to said bulb and having an opening and teeth projecting into said opening and en- .gagmg the flange on said washer, an outer threaded lamp base shell mounted to turn on said button and on said inner shell, and means for operatively connecting said shells for movement in unison when said inner shell is turned in one direction.

5. An electric lamp comprising a bulb, a button, a tube passing through said button, a flanged-washer carried by the inner end of said tube, an inner lamp base shell secured to said 'bulb and having an opening and teeth projecting into said opening and en gaging the flange on said washer, an outer threaded lamp base shell mounted to'turn on said button afidon said inner shell, and means carried' by said inner shell for engaging and turning said outer shell when said inner shell is turned in one direction.

6. An electric lamp comprising a bulb, a button, a tube passing through said button and provided with a contact member, a conductor connecting said contact member and bulb, a flanged washer carried by the inner end of said tube, an inner lamp base shell secured to said bulb and having an opening and teeth projecting into said opening and normally engaging said washer, an outer threaded lamp base shell having a pair of one of said shoulders and relative longituin presence of two witnesses.

dinal movement of said shells to bring said pawl into a position to cooperate with the 1 5 other of said shoulders disengaging said Witnesses: v

teeth from said washer and breaking said A. M. WOOSTER,

conductor. S. W. ATHERTON.

tively, said pawlnormally cooperating with In testimony whereof I aflix my signature HARVEY HUBBELL. 

